Stacking ND filters - DPChallenge Forums

02/03/2006 02:16:12 PM · #1

Have people had success? I find that when shooting water with a 2-stop, I pretty well can't get the times I'm looking for more than an hour after sunrise (on a mainly overcast day). I'd like 4-stops or even more.

Was wondering how fast the image degrades when you add more filters. I've already tried adding my polarizer on, but that only gets me 1/3rd to 2/3rd stops further...

Brent_Ward

Canon EOS-5D

Canon EF 85mm f/1.2L USM

02/03/2006 02:17:25 PM · #2

Originally posted by DrAchoo:

A Polarizer should be an additional 2 stops.

I usually only have to use a polarizer and iso 50 on a cloudy day or in the shade to get good shutter speeds.

Message edited by author 2006-02-03 14:18:20.

cresus

Canon EOS-5D Mark III

02/03/2006 02:19:58 PM · #3

I usually use an ND8 + Circular Polarzier to get 2s exposure at f/8 mid day. The polarizer adds that 1.5 stop that helps a bit (also cuts a lot of the reflections that would otherwise blow it out).

Message edited by author 2006-02-03 14:21:03.

02/03/2006 02:20:52 PM · #4

There is no way I'm getting 2 stops out of my polarizer, and I'm sure I got one that works just fine. I'll test again at home.

I'm looking for speeds of 2-4 seconds though Brent. Think waves, not waterfalls.

Brent_Ward

Canon EOS-5D

Canon EF 85mm f/1.2L USM

02/03/2006 02:24:02 PM · #5

Originally posted by DrAchoo:

Are you stopping down to at least f16?

Every polarizer I've ever used has been a 2 stop loss. or close to it.

02/03/2006 02:28:31 PM · #6

Well, I looked back at some RAW data. I managed to get to 2.5sec at f/22 ISO100 with the filter and polarizer at noon in January, but that was in deep shadow. But I remember trying a shot 30 minutes earlier that wasn't in shadow and having real trouble even getting to 1/4th.

cresus

Canon EOS-5D Mark III

02/03/2006 02:43:22 PM · #7

I just checked my Hoya HMC C-PL and it was exactly 2 stops. So with the ND8 I'm getting 5 stops total.

Canon EF 70-300mm f/4.5-5.6 DO IS USM

02/03/2006 03:42:26 PM · #8

Yup, Brent was right. I got 1 2/3rd stops. However, I was also correct in that it "isn't enough". While I can get down to 2 seconds pointing it at the woods in my backyard, seascapes tend to be pretty bright and when I simulate it by pointing at an overcast sky, I can only get down to 1/4 at ISO 100 and F22.

Which makes me wonder about stacking 2 2-stop ND filters and the Polarizer. Sounds like bad news for image quality for me.

cpanaioti

Canon EOS-40D

02/03/2006 03:43:24 PM · #9

Originally posted by DrAchoo:

Only one way to find out. Experiment.

Falc

Canon EOS-1D Mark III

Canon EF 16-35mm f/2.8L USM

02/03/2006 03:46:41 PM · #10

I quite regularly use 3 or 4 NDs / ND Grads stacked - no problem.
I use cokin 'P' series filters.

Gordon

RIM BlackBerry Curve

Canon RF 24-70mm f/2.8 L IS

02/03/2006 03:49:03 PM · #11

Originally posted by Brent_Ward:

Every polarizer I've ever used has been a 2 stop loss. or close to it.

Aren't they pretty much a variable ND, between 1 & 2, depending on how you've polarised them ?

kirbic

Canon EOS R5

02/03/2006 03:56:22 PM · #12

I've run into the same issue, and also have used stacked ND8 and C-POL filters, and also still wanted longer exposures in some situations. Shooting at f/22 with stacked filters is guaranteed to soften things up a little bit (just the f/22 will do that) so for landscape work, I'd sure rather be down at f/16 of even f/11. I've been thinking about getting a really heavy-duty ND filter, something like a 10-stop. For the amount I'd use it, it has been low on my priority list. B+W makes them and they are sold at B&H. The available densities are as follows:

BW101 (ND.3) (exposure adjustment = 1 stop)

BW102 (ND.6) (exposure adjustment = 2 stops)

BW103 (ND.9) (exposure adjustment = 3 stops)

BW106 (ND1.8) (exposure adjustment = 6 stops)

BW110 (ND3.0) (exposure adjustment = 10 stops)

BW113 (ND4.0) (exposure adjustment = 13 stops)

BW120 (ND6.0) (exposure adjustment = 20 stops)

Edit: The above are about $105 USD in 77mm size.

Message edited by author 2006-02-03 15:57:00.

Gordon

RIM BlackBerry Curve

Canon EF-S 10-22mm f/3.5-4.5 USM

02/03/2006 03:57:35 PM · #13

y'all could get up earlier ;) The light's better anyway...

mycelium

Canon EOS-350D Rebel XT

02/03/2006 04:33:07 PM · #14

Originally posted by kirbic:

Shooting at f/22 with stacked filters is guaranteed to soften things up a little bit (just the f/22 will do that)

Whoa! This is off the main topic of this thread, but this still is counter to what I thought. I had understood DOF & sharpness to increase consistently when stopping down. Is this not so? Is f/16 sharper than f/22? how about f/29?

Thanks.

cpanaioti

Canon EOS-40D

Canon EF 70-300mm f/4.5-5.6 DO IS USM

02/03/2006 04:38:06 PM · #15

Originally posted by mycelium:

Originally posted by kirbic:
Shooting at f/22 with stacked filters is guaranteed to soften things up a little bit (just the f/22 will do that)

Whoa! This is off the main topic of this thread, but this still is counter to what I thought. I had understood DOF & sharpness to increase consistently when stopping down. Is this not so? Is f/16 sharper than f/22? how about f/29?

Thanks.

It's related to diffraction (?spelling). The quality of the image will degrade the further away from the sweet spot. Better lenses have a much broader sweet spot. Cheaper lenses the sweet spot is somewhere between f8 and f16. (from what I've read and experienced with my cheap lenses)

front_element

Nikon D700

Nikon AF-S NIKKOR 24-70mm f/2.8G ED

02/03/2006 04:39:08 PM · #16

Originally posted by mycelium:

In General lenses are sharpest mid way through the f stop range. For most this is between f5.6 to f11. At the extremes (wide open or fully stopped down) sharpness is almost always lower.

Gordon

RIM BlackBerry Curve

02/03/2006 04:40:50 PM · #17

Yeah, DOF doesn't have much of anything to do with sharpness.

Sharpness is considered in the bit of the scene that's in focus, DoF just varies the amount of the scene that is in focus, not how sharp those parts are.

most lenses get better towards f8 or so then steadily worse from there.

02/03/2006 05:25:11 PM · #18

I usually do get up early Gordon, but when you want the tide to be in a certain spot and only have certain days to shoot, you are stuck. I'm planning on shooting on Monday and I bet the tide is going to be in the right place at about 10:00 AM.

elsapo

Canon EOS-5D Mark II

Canon EF 50mm f1.2L

02/04/2006 01:26:38 PM · #19

So can you stack 2 ND 8x filters together? making it a 6 stop right?

Nikon AF-S DX Zoom-Nikkor 18-70mm f/3.5-4.5G IF-ED

02/04/2006 01:29:58 PM · #20

Originally posted by elsapo:

So can you stack 2 ND 8x filters together? making it a 6 stop right?

Well, that was my original question. I don't want to go buy another ND filter if I'm just going to get a crappy picture.

I may goof with "in-camera" dodging. Moving a black piece of paper across the lens rapidly back and forth should effectively lower the light intake.

Tycho

Nikon D70

02/04/2006 01:35:21 PM · #21

I have gotten good results stacking ND's and polarizer (e.g. this and this photo). But I also have this Singh-Ray ND in my wish list.

Sony DT 18-70mm f/3.5-5.6 Aspherical ED Zoom Lens for Sony Alpha

02/04/2006 01:39:14 PM · #22

Originally posted by Tycho:

I have gotten good results stacking ND's and polarizer (e.g. this and this photo). But I also have this Singh-Ray ND in my wish list.

I like your shots Tycho. I've already manged to get 4-stops with my 2-stop ND and polarizer. Dare I add a third filter?

In seascapes, as I'm sure you know, I just need to avoid blowing the highlight on the water and the sky. This is why I think the black paper trick may work. I only need to reduce it enough to get those highlights down a bit.

Message edited by author 2006-02-04 13:40:14.

kiwinick

Sony DSLR-A550

02/04/2006 01:56:51 PM · #23

shooting st f22 or belw you encounter problems with the diaphram blades which softens the image

Originally posted by mycelium:

eschelar

Canon EOS-7D

Canon EF-S 17-55mm f/2.8 IS USM

02/07/2006 01:05:24 AM · #24

Diffraction is an affect of small apertures but is usually calculated based on the size of your pixels. Cameras with smaller pixels will not be able to stop down their aperture as narrow as cameras with bigger pixels.

The Canon 5D can shoot at F29 with a rather minimal diffraction effect, but a 20D will start to lose sharpness quite noticeably.

Someone in another thread posted a link to a site called Cambridge in Colour which had a little part on the webpage that would allow you to see the difference in pictures taken with different sensors and different apertures. The effect starts around F/14 on a 20d and becomes quite significant beyond F/22.

A camera like the 1D or the 1Ds, or 1D mk II series will perform better. I think the 1Ds was like 4MP or something? I forget now and I have to go so I can't do the research.

Not that you will go out and buy a 2nd hand 1Ds though...

Shooting with stacked filters at f/16 or even f/11 will definitely be preferable on something like the 20D or Rebel series.

The D2H should be pretty much ok here.